IPERCOOL — Result In Brief

Astronomical archives meet the world's coolest star

Sometimes described as failed stars, brown dwarfs straddle the line between stars and planets. An EU-funded initiative brought together some of the world's leading experts to get new insight into these peculiar celestial objects.

Brown dwarfs are too big to be considered planets. On the other hand, they do not have sufficient material to fuse hydrogen in their cores to develop into stars. These celestial objects that are cold and faint without an internal source of energy have recently attracted the attention of observatories worldwide.

Deep optical and infrared surveys have discovered these extremely cool objects in large numbers. However, analysing all the disparate datasets to map out the lower end of the Hertzsprung-Russell diagram requires coordinated efforts and close collaboration.

The EU-funded project IPERCOOL (Interpretation and parameterization of extremely red cool dwarfs) grouped in a single network the Torino Observatory, the Centre for Astrophysical Research at the University of Hertfordshire, the National Brazilian Observatory and the Shanghai Astronomical Observatory.

Project partners shared observational campaigns aiming to determine the distance for over 200 new objects. Distances were needed to characterise benchmark systems that provide constraints on fundamental parameters such as mass, age and metallicity.

The addition of proper motions, colours and spectra helped IPERCOOL scientists to exploit the new datasets to test atmospheric models and chart the history of brown dwarf formation. These parameterised observations have been gathered in a growing database.

IPERCOOL has built collaborations needed to exploit the wealth of observations accumulated to gain new insights into astrophysical questions that remain unanswered.